In industry, aquaculture and domestic applications in which rely heavily on water supply, it's important to control the water quality at a desired condition.
Water containers used to haul and store water for human and animal consumption, water for household use, and water for agricultural chemical spraying. Such applications require relatively pure and uncontaminated water.
In one important aspect, algae growth in a small amount of water retained in the container over a significant period of time can be considerable, which is highly undesirable.
Algae induce many problems: clogging of filters in water filtration devices, exhaustion of dissolved oxygen, and suffocation of fishes and shellfishes to death.
Algae come in many forms. There are microscopic, one-celled algae, filamentous algae that resemble hair, algae that grow in sheets and macroalgae that look like plants. There are even algae that live inside the outer integument (“skin”) or calcium shell of some corals, anemones, and other sessile invertebrates called zooxanthellae. There are slimy-looking algae that are often not algae at all, but a colony of primitive photosynthetic organisms known as cyanobacteria. There are also very hard-to-remove little dots of green that sometimes grow on aquarium panels which also are not algae, but diatom or radiolarian colonies (microscopic, one-celled, animals with hard shells) with algae incorporated in their matrix.
In an aquarium, algae growth is inevitable. Algae consume nutrients in the aquarium that if allowed to accumulate, are harmful to fish.
Algae control can be divided into three or four categories: In general on the basis of most to least appropriate in terms of long term cost, safety and ease of use these are biological, mechanical, physical and chemical controls. A few pertinent facts hold for all methods of algae control.
Turbo and Astrea snails, some blennies, some tangs, among others are good grazers. Snails are the most widely used scavengers, and generally the best choice. Some parts of the country seem to favor the use of sea urchins, dwarf angels. The former die too easily and move the decor about, and the latter can be problematical with eating expensive invertebrates.
State of the art methods include functional protein skimmers, with or without ozone and ultraviolet sterilizers. These physical filters remove and destroy algae on exposure and help oxidize nutrients as the water is circulated.
Using any chemical to control algae is the least desirable route in terms of safety and long term effect. There are several brands of antibiotic (Erythromycin, or equivalent generic name) on the market; all should be avoided from different viewpoints. The problem being they treat the symptoms only without dealing with the cause(s) of the algae problem. The factors can contribute to water system being out of balance. There are the obvious downsides of altering the chemical “evolution” of water system as well. Leave us not forget anti-biotic means “against life”.
In commercial and public aquaria settings copper, usually in some format of copper sulfate solution is employed as an algicide, as well as a general epizootic parasite preventative. If you have or ever intend to keep invertebrates, macro-algae, live rock in the system do not get involved in using copper. This metal is superb in treatment and quarantine tanks, dips and fish-only arrangements. The trade uses it extensively; but it is persistent and toxic to all life, especially non-fish.
If using a chemical algicide, great care on the dosage must be taken and be on the lookout for below acute toxic side effects. Several products state that under “bad conditions” the dosage may be doubled or tripled. It causes inconvenient to practice in algae control.
Most algaecidal agents available in market are formulated as liquids; however, such liquid formulations have certain disadvantages, notwithstanding their overall effectiveness in eradicating algae. For example, liquid algaecidal agents comprising sodium hypochlorite have limited shelf lives, generally ranging from six to eight months. Transportation of liquid formulations can also be expensive and hazardous if large quantities of the algaecidal composition are desired (generally, a gallon solution comprises about 10% of sodium hypochlorite). A concentrated algaecidal solid formulation can be more easily shipped.